It's been mentioned. It's been linked to. Now here it is, a big ol' list of Sinful Colors UPC's and Walgreens stock numbers. With this list, you can have a sales associate help you find a shade at another Walgreens.
This list will probably be an eternal work-in-progress. So far I mostly have this year's LE's and a handful of SinfulShines. Click the tabs at the bottom of the sheet to switch pages.